Aloe vera is very cold in energy so you do need to be very careful when using it as it can affect energy flow within the body. It can badly affect the mood too for some people as it affects the Liver function causing Liver Qi stagnation which can cause depression, Anger and irritability and possibly more extremes.
I took a fairly inexpensive Aloe vera juice from GNC, an own brand and it had the most dramatic effect of any Aloe vera has ever had. It badly affected my state of mind but on the positive side it did heal an area of my nervous system in my kidney/brain. For that I am thankful but the negatives were of concern. After I stopped it, it became unavailable, my mood and state of mind returned to normal. I did take turmeric along with it which might of contributed to the effect.
I also purchased some Aloe extract capsules from the states, expensive stuff and it was hopeless. No positive effect whatsoever.
You can get stronger Aloe Vera, often called Aloe Gold which has much higher MPS content than the standard stuff which is around 1,000 whereas the Aloe Gold can be 7,000, 17000 and sometimes higher depending upon the brand. The ESI brand is 7,000 MPS and is fairly cost effective ie not much more expensive than the regular 1,000 brands with Aloe Science council approval.
With regard to your son and his fistula, I do have some concern about DMSO knowing it's solvent properties. I have some Aloe/DMSO gel for the skin which I have not used a great deal because of all the messing around it takes with cleaning the skin, sterilizing it and then applying it. DMSO drives things into tissues so strongly which is why I proceed so cautiously when using it. I would not even apply it using a finger. Potentially it could of been responsible for his fistula as it can drive bacteria into the body and infections can cause fistulas.
If using Aloe with CS, how would you get around the fact that it is unlikely to be distilled and could affect the CS. It could carry a charge which could affect Ionic silver.